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eed6a9a957
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Alexei Starovoitov eed6a9a957 Merge branch 'perf: Add mmap2 build id support' 
Jiri Olsa says:

====================

hi,
adding the support to have buildid stored in mmap2 event,
so we can bypass the final perf record hunt on build ids.

This patchset allows perf to record build ID in mmap2 event,
and adds perf tooling to store/download binaries to .debug
cache based on these build IDs.

Note that the build id retrieval code is stolen from bpf
code, where it's been used (together with file offsets)
to replace IPs in user space stack traces. It's now added
under lib directory.

v7 changes:
  - included only missing kernel patches, cc-ed bpf@vger and
    rebased on bpf-next/master [Alexei]

v6 changes:
  - last 4 patches rebased Arnaldo's perf/core

v5 changes:
  - rebased on latest perf/core
  - several patches already pulled in
  - fixed trace+probe_vfs_getname.sh output redirection
  - fixed changelogs [Arnaldo]
  - renamed BUILD_ID_SIZE to BUILD_ID_SIZE_MAX [Song]

v4 changes:
  - fixed typo in changelog [Namhyung]
  - removed force_download bool from struct dso_store_data,
    because it's not used  [Namhyung]

v3 changes:
  - added acks
  - removed forgotten debug code [Arnaldo]
  - fixed readlink termination [Ian]
  - fixed doc for --debuginfod=URLs [Ian]
  - adopted kernel's memchr_inv function and used
    it in build_id__is_defined function [Arnaldo]

On recording server:

  - on the recording server we can run record with --buildid-mmap
    option to store build ids in mmap2 events:

    # perf record --buildid-mmap
    ^C[ perf record: Woken up 2 times to write data ]
    [ perf record: Captured and wrote 0.836 MB perf.data ]

  - it stores nothing to ~/.debug cache:

    # find ~/.debug
    find: ‘/root/.debug’: No such file or directory

  - and still reports properly:

    # perf report --stdio
    ...
    99.82%  swapper          [kernel.kallsyms]  [k] native_safe_halt
     0.03%  swapper          [kernel.kallsyms]  [k] finish_task_switch
     0.02%  swapper          [kernel.kallsyms]  [k] __softirqentry_text_start
     0.01%  kcompactd0       [kernel.kallsyms]  [k] _raw_spin_unlock_irqrestore
     0.01%  ksoftirqd/6      [kernel.kallsyms]  [k] slab_free_freelist_hook
     0.01%  kworker/17:1H-x  [kernel.kallsyms]  [k] slab_free_freelist_hook

  - display used/hit build ids:

    # perf buildid-list | head -5
    5dcec522abf136fcfd3128f47e131f2365834dd7 /proc/kcore
    589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
    94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
    559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
    40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so

  - store build id binaries into build id cache:

    # perf buildid-cache -a perf.data
    OK   5dcec522abf136fcfd3128f47e131f2365834dd7 /proc/kcore
    OK   589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
    OK   94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
    OK   559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
    OK   40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
    OK   a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
    OK   e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
    OK   9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find

    # find ~/.debug | head -5
    /root/.debug
    /root/.debug/proc
    /root/.debug/proc/kcore
    /root/.debug/proc/kcore/5dcec522abf136fcfd3128f47e131f2365834dd7
    /root/.debug/proc/kcore/5dcec522abf136fcfd3128f47e131f2365834dd7/kallsyms

  - run debuginfod daemon to provide binaries to another server (below)
    (the initialization could take some time)

    # debuginfod -F /

On another server:

  - copy perf.data from 'record' server and run:

    $ find ~/.debug/
    find: ‘/home/jolsa/.debug/’: No such file or directory

    $ perf buildid-list | head -5
    No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
    5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
    5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
    589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
    94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
    559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so

  - report does not show anything (kernel build id does not match):

   $ perf report --stdio
   ...
    76.73%  swapper          [kernel.kallsyms]    [k] 0xffffffff81aa8ebe
     1.89%  find             [kernel.kallsyms]    [k] 0xffffffff810f2167
     0.93%  sshd             [kernel.kallsyms]    [k] 0xffffffff8153380c
     0.83%  swapper          [kernel.kallsyms]    [k] 0xffffffff81104b0b
     0.71%  kworker/u40:2-e  [kernel.kallsyms]    [k] 0xffffffff810f3850
     0.70%  kworker/u40:0-e  [kernel.kallsyms]    [k] 0xffffffff810f3850
     0.64%  find             [kernel.kallsyms]    [k] 0xffffffff81a9ba0a
     0.63%  find             [kernel.kallsyms]    [k] 0xffffffff81aa93b0

  - add build ids does not work, because existing binaries (on another server)
    have different build ids:

    $ perf buildid-cache -a perf.data
    No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
    FAIL 5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
    FAIL 5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
    FAIL 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
    FAIL 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
    FAIL 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
    FAIL 40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
    FAIL a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
    FAIL e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
    FAIL 9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find

  - add build ids with debuginfod setup pointing to record server:

    $ perf buildid-cache -a perf.data --debuginfod http://192.168.122.174:8002
    No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
    OK   5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
    OK   5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
    OK   589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
    OK   94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
    OK   559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
    OK   40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
    OK   a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
    OK   e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
    OK   9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find

  - and report works:

    $ perf report --stdio
    ...
    76.73%  swapper          [kernel.kallsyms]    [k] native_safe_halt
     1.91%  find             [kernel.kallsyms]    [k] queue_work_on
     0.93%  sshd             [kernel.kallsyms]    [k] iowrite16
     0.83%  swapper          [kernel.kallsyms]    [k] finish_task_switch
     0.72%  kworker/u40:2-e  [kernel.kallsyms]    [k] process_one_work
     0.70%  kworker/u40:0-e  [kernel.kallsyms]    [k] process_one_work
     0.64%  find             [kernel.kallsyms]    [k] syscall_enter_from_user_mode
     0.63%  find             [kernel.kallsyms]    [k] _raw_spin_unlock_irqrestore

  - because we have the data in build id cache:

    $ find ~/.debug | head -10
    .../.debug
    .../.debug/home
    .../.debug/home/jolsa
    .../.debug/home/jolsa/.cache
    .../.debug/home/jolsa/.cache/debuginfod_client
    .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7
    .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable
    .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7
    .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7/elf
    .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7/debug

Available also in:
  git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  perf/build_id

thanks,
jirka
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-01-14 19:29:59 -08:00
arch bpf: Add bitwise atomic instructions 2021-01-14 18:34:29 -08:00
block SCSI fixes on 20210101 2021-01-01 12:58:07 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: ecdh - avoid buffer overflow in ecdh_set_secret() 2021-01-03 08:35:35 +11:00
Documentation bpf: Document new atomic instructions 2021-01-14 18:34:30 -08:00
drivers bpf: Rename BPF_XADD and prepare to encode other atomics in .imm 2021-01-14 18:34:29 -08:00
fs poll: fix performance regression due to out-of-line __put_user() 2021-01-08 11:06:29 -08:00
include perf: Add build id data in mmap2 event 2021-01-14 19:29:58 -08:00
init Revert "init/console: Use ttynull as a fallback when there is no console" 2021-01-08 11:02:18 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel perf: Add build id data in mmap2 event 2021-01-14 19:29:58 -08:00
lib bpf: Add size arg to build_id_parse function 2021-01-14 19:29:58 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm: make wait_on_page_writeback() wait for multiple pending writebacks 2021-01-05 11:33:00 -08:00
net bpf: Allow to retrieve sol_socket opts from sock_addr progs 2021-01-12 14:44:53 -08:00
samples bpf: Rename BPF_XADD and prepare to encode other atomics in .imm 2021-01-14 18:34:29 -08:00
scripts gcc-plugins: fix gcc 11 indigestion with plugins... 2021-01-06 15:08:23 -08:00
security Provide a fix for the incorrect handling of privilege 2020-12-24 14:08:43 -08:00
sound sound fixes for 5.11-rc3 2021-01-05 13:25:49 -08:00
tools bpf: Add tests for new BPF atomic operations 2021-01-14 18:34:29 -08:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt ARM: 2020-12-20 10:44:05 -08:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap RDMA 5.11 pull request 2020-12-16 13:42:26 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-11 22:29:38 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-08 13:28:00 -08:00
Makefile Linux 5.11-rc2 2021-01-03 15:55:30 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.